Method of mending cracked engine blocks and the like



23, 1941-. c; A. KERKLING METHQD OF MENDING CRACKED ENGINE BLOCKS AND THE LIKE Filed Nov. 8, 1959' 4 Sheets-Sheet l 11. 23; 1941. I c, @RKUNG 2,267,033

METHOD OF MENDING CRACKED ENGINE BLOCKS AND THE LIKE Filed Nov. 8, 1959 '4 Sheets-Sheet a Patented Dec. 23, 1 941 UNITED STATES PATENT OFFICE amps:

METHOD OF CRACKED ENGINE BLOCKS AND THE LIKE Clarence Antonio Kerlr'linL'Bloomington, ind. Application November 8, 1939, Serial No. 308,468

, 1 Claim.

This invention .relates toimproved methods of mending cracked blocks of engines and thelike, and more particularly to methods for mending cracks in blocks of internal combustion engines.

Every year there are thousands of expensive cylinder blocks from engines of automobiles, trucks, tractors, buses and the like, discarded because of cracks caused by freezing, by undue strain, or by rapid and uneven temperature changes. While, as indicated, some of these cracks are caused by undue strain, or rapid and uneven heating or cooling, thegreatest percentage are in liquid cooling engines and are the result of freezing of the engines cooling fluid.

Many different methods and products have been experimented with over a period of many years, in an attempt to make permanent repairs of such cracks, but such methods and products that have hereto been tried have in most instances proved unsuccessful and have therefore largely been abandoned.

Welding and brazing processes, while theoretically ideal, have not worked out well, and have largely been abandoned, due to troubles arising from localized high temperature heating of small sections of the engine block.

Another method which has been hereto extensively tried in an attempt to produce permanent repairs in cracked cylinder blocks, consists in filling the engines cooling system with a liquid containing substance that will deposit on the walls of the crack, under seepage of the fluid therethrough; and eventually close the crack. However, such methods have largely failed to provide a permanent repair of cracked cylinder blocks for the following reasons, to wit:

A. The first reason for failure of such methods is the fact that cracks of any great magnitude usually weaken the wall structure on one or both sides of the crack to the extent that there is a continual relative vibration or movement set up between block portions on opposite sides of the crack under operating conditions, which'results in either preventing the formation of a proper seal, or a dislodgement of a seal once made.

B. In the second place,. in cases where the cracks are of material length, and particularly when the cracks are caused by freezing, the cracked wall is apt to be bulged so that the opening of the crack is quite wide, and in fact,

pound, which when run through the engines circulating system, will accumulate on the walls of the crack under seepage of the fluid through thecrack, and seal up the crack; and which, when finally set, will have great tensile strength,

1 will have expansion and contraction characteristics so closely corresponding to that of the engine block metal that a permanent seal will be made, at least in the absence of relative vibration between-opposite walls of the crack.

Another important object of the invention is an improved method of sealing cracks in engine blocks through the use of primarily fluid sealing substances or compounds applied through the engines cooling system. Unto this end, the improved methods herein defined in the claim include the step or steps of mechanically closing such cracks to a minimum and/or permanently restraining the opposite walls of the crack from relative vibration, so as to reduce the open area to a minimum before application of the fluid sealing substance and/or reduce to a minimum the stresses and strains applied to the subsequently formed seal during operation of the engme.

2. Cracks adjacent the base line of the block and running through its main bearing support.

' 3. Cracks through a valve seat and entering the fluid chamber and sometimes extending to an adjacent cylinder.

Both the improved methods and product hereof have proven highly successful in permanently repairing the above noted types and other types of cracks in engine cylinder blocks and are now being used commercially on a wide scale.

The above and other objects and advantages of too wide to permit of an efficient seal by the last described process.

C. A further reason for failure of such methods seems to be the absence of a primarily fluid sealing compound, which when hardened in the crack of the engine block, will have the necessary lasting and staying qualities.

This invention has as one of its objects, the provision of a liquid sealing product or comeral views:

the invention will be made apparent in the following specification, claim, and appended drawings.

Referring to the drawings, wherein like characters indicate like parts throughout the sev- Fig. 1 is a fragmentary perspective view of one cylinder-contaming bank of the cylinder block of a Ford v8 engine;

Fig. 2 is a fragmentary transverse sectional view taken on the line 2-2 of Fig. 1;

Fig. 3 is a fragmentary bottom perspective view of the cylinder block of a Ford V8' engine; Fig. 4 is a. detail fragmentary sectional view taken on the line 4-4 of Fig. 3;

Among the various different types of cracks which .have been successfully repaired through Fig. 5 is a detail fragmentary sectional taken on the line 5-5 of Fig. 3;

Fig. 6 is a fragmentary top perspective view somewhat similar to Fig. 1, but showing the opposite side of the engine cylinder bank of the block;

Fig. 7 is an enlarged fragmentary detail view taken on line 'I! of Fig. 6;

Fig. 8 is a fragmentary detail view illustrating on an enlarged scale a small'portion of the block shown in Fig. 6 but showing this'portion of the block as it appears after a channelhas been out along the line of the: crack;

Fig. 9 is a detail sectional view taken on line 9-9 of Fig. 8;

Figs. 10 and 11 are views similar to Fig. 9, but illustrating diiferent steps in the method of mending cracks of the type exemplified in Fig. 6; and

Fig. 12 is a view similar to Fig. 8, but illustrating the same after the crack has been completely repaired.

The engine block herein illustrated, for the purpose of example, and which is indicated as an entirety by l3, happens to be the cylinder block of a Ford V8 engine. This cylinder block I3, which, of course, includes two angularly disposed cylinder bank sections, each containing four cylinders l4. However, for the purpose of illustration in this case it is only necessary to show one bank of cylinders, and hence the other bank thereof has been omitted. In accordance with conventional practice, this block is a cast structure formed to provide the cylinders I4, and valve seats [5 and valve ports it. The cylinders view l4, and valve port It are surrounded by a cooling first be described. By reference particularly to fluid circulating chamber IT. The flat top surface of the cylinder block, upon which the cylinder head is applied, is provided with tapped cylinder-head bolt-receiving holes l9, and water passages or ports 20. By particular reference to Fig. 3 it will be, seen that in this engine, as in most engines, thelower portion of the cylinder block below the cylinders forms the upper portion of the crank chamber, which is normally closed by a removable crank-case completing oil pan, not shown. The marginal bottom edge portions of the cylinder block are provided with tapped holes 2| for reception of oil pan retaining bolts, not shown and, as will be seen particularly by reference to Figs. 3 and 4, thewalls of the block are double nearly down to this lower edge so as to extend the cooling fluid circulating chamber nearly to the bottom of the block. In Fig. 3, one-half of an end crank-shaft main bearing is shown at 22, and one-half 'of a central crankshaft main bearing is shown at 23. The bearing I .23 is in a partition-like main bearing support 24 that extends transversely across the interior of the cylinder block within the crank portion thereof and which is an integral part of the block. The engine's cam shaft is shown at 24a in Fig. 3. The type of cracks shown in Figs. 1 and 2, and the method of mending or repairing the same, will Fig. 1,-it will be seen that there are three cracks identified as a, b, and 0 respectively, in oneside wall of the block. This type of cracking in a cylinder block is usually caused by freezing of the cooling fluid, and causes bulging of that 7 portion of the block lying between cracks aand b.

Hitherto, this type of crack has been very dif-" ficult .to seal up by means of sealing fluids because of the relatively wide open condition of the Ill \brating movement between the walls on opposite sides of the crack. However, the novel method presently to be described in detail has been found to make a very permanent repair of such cracks at low cost.

The first step or series of steps in the preferred method of repairing blocks cracked in the manner shown in Fig. 1, consists in drilling a hole, indicated by 25 in Fig. 2, in an outer wall of the cylinder block, and which wall forms one of the outside walls of the fluid chamber H, at a point preferably intermediate the cracks a and b, if there be two such cracks, and at point preferably intersecting the intermediate crack c, if this crack c is also present. However, in case there be but one crack, this hole c would be made either through the single crack or through the wall at the side thereof that was most in need of support. For example, if only crack a or crack b was present, the hole could be made substantially as shown, since it would then be through the weakest portion of the block. Also in' case only crack 0 was present, or a combination of cracks a and c, or b and c, the hole could be located substantially as shown, preferably intersecting the crack 0. By reference to Fig. 1, it will be seen that that portion of the block wall lying between cracks a and b is entirely. broken loose, since both of these cracks terminate in the port 20. After a hole 25 has been drilled, a similar hole is drilled in the opposite outside wall of the block cylinder bank located at the opposite side of the line of cylinders l4 and forming the other extreme outside wall of the water chamber ll. This second hole, indicated by 25, .is preferably placed in line with the space between two adjacent cylinders l4, and this regardless of whether it is in true alignment, transversely of the block, with the hole 25. This second hole 26 will probably be .located in as nearly as possible, in the same spaced relation from the top of the block as is the hole 25, but if necessary, or more convenient, it can be located at a different position with respect to the top nut 28 is now applied to the outer screw-threaded end of the bolt 21 and this nut is screwed up on the bolt gradually until the .bulged portion lying between cracks a and b is pulled up firmly against the adjacent portions of the block, so as to very nearly close the cracks and firmly support that portion against vibration. In practice, it has been found that this tightening operation may be carried out most effectively by tapping with a hammer on the head end of the bolt while tightening the nut. .It has been found advisable in many instances to dip the head and screw threaded end pound such as the one forming part of this invention, and hereinafter described, before applicracks and because of the relatively greatvi- 7 cation of the bolt to the holes. This sealing compound will tend to seal up the clearance between the bolt and holes before the final sealing process "is started. Another sealing product valuable for this particular purpose is obtainable on the market under the trade name Permatex No. 1," and this substance can also be worked into the holes around the parts to be engaged between bolt head and nut. Also. it is sometimes further desirable to wind a little soft yarn or string around the bolt beneath the head and nut to aid in the initial sealing of these points.

The next step or steps in mending the crack, exemplified in Figs. 1 and 2 includes filling the engines fluid circulating system, inclusive of the engine block chamber H, with a liquid having the required sealing qualities such, for example, as the primarily fluid sealing compound of this invention, and which is hereinafter disclosed. Assuming that this step of the process is to be carried out with my improved fluid sealing comound, this is mixed with water in the fluid circulating system to the approximate proportions holes in the walls of the block and a bolt or bolts are also passed through the hole or holes in the given in connection with the formula hereinafter recited. When this has been done, the engine is set in operation and permitted to idle until the circulating fluid, including the sealing compound, has reached the boiling point and boiled for a short period of time. During this time, the fluid containing the sealing substance will seep through the nearly closed cracks a, b, and c, and perhaps,

to some extent around the head and nut of bolt 21, and will gradually build up a deposit on opposite walls of the cracks of other openings until the same have become completely sealed or healed, at which time all seepage or leakage of water from the. circulating system will cease. By running the motor up to the boiling temperature of the fluid, the cracks are expanded to the maximum which, will be encountered in engine service. Therefore, it will be evident that by running the motor at this temperature until the 'cracks are. completely sealed it will provide a seal of very permanent nature, since the sealing substance thereafter will normally be placed under somewhat of a pressure by the opposite walls of the crack. I

In accordance withthe preferred practice, the engine will be run for a total of about two hours, with a fluid compound in the fluid circulating system. Afterwards the fluid system may be drained and refilled with a suitable cooling medium such as water or any of the popular types of anti-freeze solutions. In this manner, the cracks shown in Figs. 1 and 2 can be permanently repaired without disassembling the engine to any material extent.

In Figs. 3, 4, and 5, a long crack d, is illustrated as running along the lower edge of the inner wall of the engine block and through the main bearing support 24. This type of crack is frequently found in particular in Ford V8 engines and hitherto has caused the discarding of a great many of these blocks. This crack is through the inner wall of the lower extreme portion of the therefore result not only in leakage of water into the engines crank chamber, but also produces a serious weakening of the main bearing support 24. To-repair this type of crack, the crack is first drawn together as much as possible and mechanically supported against vibration of its opposite walls, to this end a double series of main bearing support 24. Mainly for the sake' of appearance the side wall bolts, indicated by 28, have round and preferably quite thin heads, which are located on the outside of the block, while the nuts are applied to the inside thereof. The bolts of the motor support, indicated by 29, are preferably provided with angular heads,

and are extended outwardly through the holes in the main bearing support with the'nuts 30 applied on the outer ends, and washers 3| applied under the nuts. -In this case also, the bolts and nuts and the holes through which the bolts have passed should have some of the sealing compound applied thereto before application of the bolts and nuts as directed in connection with the application of bolt 21. The nuts of these bolts, 28 and 29, are alternately tightened until all thereof have been drawn up to the maximum permissible extent, which act may be aided considerably by pounding on the head ends of the bolts while tightening the nuts. Also this pounding on the heads of the bolts will cause them to Another type. of crack which has hereto result-- ed in discarding of a great many engine blocks,-

and which can be inexpensively and permanently repaired by a modification of the abovedescribed fluid chamber l1 below the cylinders and does method or methods, isshown particularly in Rigs. 6 to 12 inclusive. This type of crack extends from a valve port [6 through the valve seat l5 and into the upper portion of an adjacent cylinder I4 and is identified by e. Since this crack is through the outer wall of the fluid chamber l'l.

water or circulating fluid will, of course, leak both into the cylinder and valve port.

The first step in mending such a crack is to form in the upper surface of the block, along the line of the crack and through the valve seat I5 and-into the cylinder M, a channel 32 which is shown best in Fig. 8. This channel is usually formed by use of a small cape .chisel, and made about /4 inch wide and about /8 inch deep. This channel should follow thev contour of the valve seat and extend somewhat below it.

The next step in this modification of the method includes drilling a series of holes identified by numerals 33, 34, and 35 respectively. These holes are preferably made with about a 5 drill. Hole 33 is preferably drilled straight through the valve seat approximately at a right angle thereto, hole 35 is drilled at a right angle to the top of the block, and hole 34 is drilled at an angle about half way between the angles of holes 33 and 35.

Usually these-holes are drilled about of an inch deep and terminate at approximately a common point, each intersecting the other.

or more holes are drilled through the main bearing support intersecting crack dtherethrough.

When this is accomplished, a series of nut.-

equipped bolts are passed through the aligned Next these holes are tapped and relatively soft and ductile metal screws 33a,.34a, and 35a, are screwed into these holes. These screws 33a to 35a inclusive are bottomed into their respective holes or against others thereof. Many cracks through valve seats do not extend to the top of the cylinder and in this case screws 33a'to 35a are all that is necessary, but in some of those cases where the crack does extend to the top of the cylinder,-it is desirable to drill one hole across to the cylinder and provide an additional screw indicated by 36a, as illustrated. The screws 33a to 3611 inclusive are preferably made from bronze welding rod available on the market under the trade name Tobin. Lengths of such rod are preferably cut to length and tapped to the approximate depth of the holes. In fact that the screws are made longer than necessary and the tops thereof are bent over as shown by dotted lines in Fig. 10, is to provide wrench engaging heads. Preferably these screws will be pre- .dipped in sealing compound such as disclosed herein, which will make the process of screwing in easier and aid in the forming of a seal. After these'screws are tightened into the holes, they are cut oii materially above the tops of the channel substantially as shown in Fig. 10. Now the projecting ends of the screws are pounded down and deformed until they tightly'flll the complete channel, this being accomplished most readily by use of the peen end of a hammer. When the screw material has been worked into the channel -to tightly fill it, the surplus material still projecting above the channel is flled or ground off even with the top of the block and the valve seat is reamed or ground out so asto form a complete new valve filling surfaceover the channel which will match up perfectly with the adjacent portions of the valve seat. The finished product will now appear much as shown in Figs. 11 and 12. With this done, the crack will be sealed very nearly fluid tight, and the valve seat will be rendered serviceable for a long period of time. Also, of course, the block portions on opposite sides of the crack will mechanically be held against relative movement. It has been found that Tobin bronze not only makes ,a very durable valve seat, but apparently has substantially the same expansion and contraction qualities of the cast block material.

The final step in scaling up the crack of Figs. 6

r .to 12 inclusive consists in applying a primarily fluid sealing substance and running the motor while the substanceis in the fluid circulating system, substantially as described in connection with other figures.

The preferred form of the sealing compound of circulating system.

this invention, which is preferably employed. in

carrying out the method or methods herein described, is made up of ingredients in proportions given in the following formula.

. Preferred formula 5 gallons or pounds silicate of soda 1 pound of pulverized ginger 2 pounds of pulverized flaxseed 1 pound of aluminum powder It has been found that the'best results are obaac'maa tained by mixing the above ingredients as follows:

1. Pour four gallons of the silicate of soda into a container and start agitation through means of a mechanical mixer, which should be maintained in operation throughout the mixing operation.

2. Slowly sift two pounds of the ground flaxseed into the solution. I

3. Slowly sift in one pound of the ginger.

4. Slowly sift one pound of aluminum powder into the mixture.

5. Add the remaining one gallon of silicate of soda to the mixture.

6. If desired, three quarts to a gallon of water may be added, but this is not essential.

With all ingredients now in the mixture, agitation should be continued for about two hours, after which agitation should be maintained while pouring into cans or other air-tight containers, for distribution. The above will fill about 70 16- ounce cans.

One 16-ounce can of the solution is suflicient for repairing motors whose circulating system has a capacity of not over about six gallons, and,

when' greater capacity is encountered, two cans can be used. For making the repair, the solution should be mixed only with plain water in the What I claim is:

The method of repairing a crack formed by bulged I apart portions in a metal engine block of an internal combustion engine having a cooling system and a cooling fluid therein in communication with an engine block chamber, that includes the following steps: drawing and clamping together said bulged apart portions of said block on opposite sides of said crack until -said crack is nearly closed, without removing the engine from the vehicle in' which it is installed: holding said portions clamped in said'nearly closed position against vibration with respect to each other during the remaining steps; adding to said cooling fiuid sufiicient fluid containing a' metal sealing compound hardenable when heated to cover said crack during the remaining steps; subsequently circulating said fluid and said compound in said system and said chamber by operating said engine with said fluid and said compound at the boiling point for an extended period of time until said bulged apart portions and said engine reach maximum operating temperature; maintaining said portions at said maximum tem perature until the resulting expansion of said portions causes .said crack to reach its maximum enlargement at said temperature, and continuing the circulation of said fluid and said compound throughout said chamber until said compound .fills and hardens in said thus enlarged crack.

CLARENCE ANTONIO KERKLING. 

